Objective To explore the growing development and community succession of main sarcos-aphagous insects on pig carcasses in summer indoor and outdoor environment in Shenzhen area and to estimate the postmortem interval (PMI). Methods From early May to August in 2013, in Forensic Med-ical Examination Center of Shenzhen Public Security Bureau, the main insect species and the decomposi-tion process were observed in two adult pig carcasses of simulative indoor and outdoor environment. The different decomposition stages and the community succession of insects were recorded. Results The indoor and outdoor pig carcasses showed skeleton 412.5 and 325 hours after death, respectively. The main species of flies on pig carcasses were Chrysomya megacephala, Chrysomya rufifacies and Chrysomya chani. The main species of beetles were Crecphilus maxillosus, Necrobia ruficollis, Saprinus splendens and Dermestes maculatu. The dominant species of flies in the outdoor pig carcasses obviously produced the second generations due to the effect of mass rainfall, nor in the indoor pig carcasses. Conclusion There are regular patterns on the community succession of insects on pig carcasses in summer indoor and out-door environment in Shenzhen area. The activity patterns of seven typical insects and their larva show important value for estimating PMI.

BACKGROUND:Although vitamin C has an anti-oxidation role and can promote cell proliferation, there is a lack of research about the promoting effect of vitamin C on the proliferation of adipose-derived stem cells under high glucose conditions and the related molecular mechanisms.OBJECTIVE:To explore the promoting effect of vitamin C on the proliferation adipose-derived stem cells treated by the high glucose and the related molecular mechanisms.METHODS:Passage 3 human adipose-derived stem cells were cultured under high glucose conditions and then treated with different concentrations of vitamin C (0, 100, 150, 200, 250, 300 μmol/L). Cells cultured under low glucose conditions acted as controls. The expression levels of p-ERK and p-AKT proteins were detected by western blot. MTT method was used to choose the optimal concentration and time of vitamin C for all the subsequent tests. Human adipose-derived stem cells cultured under high glucose conditions were divided into four groups, and cells in blank control group had no treatment. Cells in the other three groups were treated with the optimal concentration of vitamin C (vitamin C group), LY294002+the optimal concentration of vitamin C (LY294002 group), or U0126+the optimal concentration of vitamin C (U0126 group) for 48 hours.EdU staining assay was used to detect the cell proliferation of human adipose-derived stem cells.RESULTS AND CONCLUSION:(1) Cell counting kit detection:We found that high glucose reduced the proliferation of human adipose-derived stem cells, and vitamin C promoted the proliferation of these cells. The best concentration of vitamin C was 200 μmol/L and the optimal effect time was 48 hours. (2) Western blot detection:Compared with the 0 μmol/L vitamin C group, the level of p-ERK in the 200 μmol/L vitamin C group was upregulated significantly (P < 0.01),while no significant expression change in p-AKT protein was found in control, 0 and 200 μmol/L vitamin C groups.(3) EdU test:the number of EdU positive cells was significantly higher in the vitamin C, LY294002, and control groups compared with the blank control group (P < 0.01). Moreover, compared with the vitamin C group, the EdU positive cells in the U0126 group were decreased significantly in number (P < 0.01). In conclusion, the ERK/MAPK signaling pathway is involved in the promotion effect of vitamin C on the proliferation of human adipose-derived stem cells under high glucose conditions.

Objective To detect the changes of microbial community functional diversity of corpses with different postmortem interval(PMI)and to evaluate forensic application value for estimating PMI. Methods The cultivation of microbial community from the anal swabs of aSusscrofaand a human corpse placed in field environment from 0 to 240 h after death was performed using the Biolog-Eco Mi-croplate and the variations of the absorbance values were also monitored. Combined with the technology of forensic pathology and flies succession, the metabolic characteristics and changes of microbial commu-nity on the decomposed corpse under natural environment were also observed.Results The diversity of microbial metabolism function was found to be negatively correlated with the number of maggots in the corpses. The freezing processing had the greatest impact on average well color development value at 0 h and the impact almost disappeared after 48 h. The diversity of microbial metabolism of the samples be-came relatively unstable after 192 h. The principal component analysis showed that 31 carbon sources could be consolidated for 5 principal components(accumulative contribution ratio >90%). The carbon source tsquare-analysis showed thatN-acetyl-D-glucosamine andL-serine were the dominant carbon sources for estimating the PMI(0=240 h)of theSusscrofaand human corpse.Conclusion The Biolog-Eco method can be used to reveal the metabolic differences of the carbon resources utilization of the microbial community on the corpses during 0-240 h after death, which could provide a new basis for estimating the PMI.

In many neurodegenerative diseases,eye movement is disrupted,which is a common and early characteris-tic of neurodegenerative diseases.Characterizing eye movement is important for the diagnosis of neurodegenerative disea-ses,helping to track disease progression and response to treatment.In recent years,eye tracking technology has been ap-plied to the assessment of cognitive function in patients with neurodegenerative diseases.Compared to traditional cognitive assessment methods,the technology has higher temporal and spatial resolution for sensitive quantification.Eye tracking da-ta confirms that executive dysfunction is common in Parkinson's disease and amyotrophic lateral sclerosis,while attention deficit is a characteristic of Alzheimer's disease and multiple sclerosis.Research using eye tracking to evaluate the cogni-tive function of epilepsy patients is still in its early stages,but this method has shown advantages.In this article,the appli-cation of eye tracking technology in neurodegenerative diseases is reviewed.